299
FXUS63 KDVN 111138
AFDDVN
Area Forecast Discussion
National Weather Service Quad Cities IA IL
538 AM CST Mon Dec 11 2017
...AVIATION UPDATE...
.SYNOPSIS...
Issued at 321 AM CST Mon Dec 11 2017
06Z surface data has an inferred boundary running from southwest
Indiana, to near KEOK, and then west of KMCW. Another inferred
boundary ran from KFSD into northern Kansas. Dew points were in the
teens and 20s from the Great Lakes and Ohio Valley into the central
and northern Plains.
&&
.SHORT TERM...(Today and Tonight)
ISSUED AT 321 AM CST Mon Dec 11 2017
Minor snow accumulations with the incoming system. A bigger concern
will be the windy conditions later today and tonight.
The main concern for the next 24 hours will be the windy conditions
developing this afternoon and evening. Winds will increase to 20 to
30 mph with gusts up to 40 mph. The strongest winds look to occur
late this afternoon and evening, or, roughly from 5 PM to midnight.
Based on trends in observational data and the RAP, the initial shot
of precipitation from the approaching system will give a glancing
blow to the area through sunrise. Mainly flurries will be seen but
some light snow is possible across northeast Stephenson county. Any
accumulation there would be a dusting at best.
After sunrise, the forcing associated with the initial round of
precipitation will move east of the area creating a lull in
activity. By mid to late morning and through the afternoon, forcing
will increase again as the low moves through the area.
Precipitation will break out across the area from mid to late
morning and continue through the afternoon. Generally areas north of
highway 30 have the best chance of seeing any precipitation.
Precipitation will take on different forms depending upon how warm
it becomes.
A rain/snow mix that may at times be all snow is expected in the
highway 20 corridor from Dubuque on east. South of the highway 20
corridor, light rain or sprinkles are expected that may mix with
some light snow or flurries during the late afternoon hours.
Accumulations by sunset will be mainly a dusting.
This evening lingering flurries/sprinkles will end east of the the
Mississippi. After midnight, dry conditions are expected.
.LONG TERM...(Tuesday through Sunday)
ISSUED AT 321 AM CST Mon Dec 11 2017
Continued overall dry to mostly dry pattern in northwest flow with
minor to moderate day to day temperature changes.
Long Term Forecast Confidence Assessment...fair or average with main
issues diurnal trends with most days highs tending too low by 2 to 3
plus degrees and some lows too mild with clear skies and light winds
by 2 to 3 plus degrees.
Tuesday through Thursday...warming trend each day with mostly fair
to fair skies. Low POPS Wednesday night are overdone and suggestive
of flurries in northeast. Highs 25 to 35, rising to 30s to lower
40s Wednesday and Thursday. Mins teens rising into mostly the 20s.
Friday through Monday...continued northwest flow with low chances
for light precipitation. Highs in the 30s and 40s, mins mostly in
the 20s.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday Morning)
ISSUED AT 528 AM CST Mon Dec 11 2017
VFR conditions will be seen through 23z/11 as a storm system
moves toward the Great Lakes. Very light rain or snow is possible
through 00z/12 that might result in brief MVFR conditions. After
18z/11 low level mechanical turbulence will increase as strong
winds arrive behind the storm system. After 23z/11 conditions
will deteriorate to MVFR as lower clouds arrive along with winds
that may gust to 37 kts. After 06z/12 VFR conditions will develop
as high pressure builds into the Midwest.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...08
SHORT TERM...08
LONG TERM...Nichols
AVIATION...08